In this study, we analyzed expressions of megakaryocyte-related genes (GP II_b, III_a, I_b and PF4) on megakaryocyte cell lines (CMK, CMK 11-5, K562) as well as megakaryocytic cells, oftained from megakaryocytic leukemia or other megakaryocyte pr13EA\ : oliferating disorders. And thus, we aimed at clarifying seguential expression of megakaryocytic genes during the course of differentiation and maturation of megakaryocytic seriese and at establishing a molecular biological procedures which enable us13EA\ : to differentiate megakaryocytic leukemias from other megakaryocyte proliferating disorders. Our results are as follows.1. Megakaryocytic cells are thought to express molecular markers, GP III_a, II_b, PPO (platelet peroxidase), GP I_b, and PF4, sequentially in these orders, as differentiation proceeds2. We developed some useful tequniques to characterize molecular-biologically megakaryocytic cells, as listed below :(1) in-situ hybridization method to delect expression of GP II_b and P
… MoreF4 to identify megakaryocytic cells(2) RT-PCR (reverse transcriptasepolymerase chain reaction) method to detect platelete specific protein genes, with special reference to GP II_b, III_a and PF4(3) in situ hybridization methode to detect IL 6 receptor of megakaryocytic cells(4) Immunobeads method to collect and enrich megakaryocytes from human bone marrow aspirate for further analytical use3. We established a new megakaryocytic cell line, of which cells showed no induction of differentiation with addition of phorbal ester, from a patient with granulocytic sarcoma. We summarized as follows.1. Megakaryocytic leukemia can be classified in 3 types from view point of gene expression, namely leukema with immature cells expressing only GP III_a, gene, one with more differentiated cells, expressing all of GP_s and one with for more differe13EA\ : ntiatiated cells, expressing all of GP_s and cytoplasmic proteins.2. Megakaryocytic leukemia, with leukemic cells expressing PF4 gene was found more responsive to chemotherapy and more chronic, as compared with the immaturetypes.3. Megakaryocytic cell lines was shown to express IL 6 and IL 6 reaptor, by using RT-PCR method. This suggests the presence of autocrine mechanism of IL 6 in proliferation and differentiation of neoplastic megakaryocytes. Less